Thousands trapped by rebels in Iraq

Several thousand civilians remain trapped by militants on a mountain
in northern Iraq and need "life-saving assistance", the United Nations
warns.

Members of the Yazidi sect fled there 10 days ago after fighters from
Islamic State seized the town of Sinjar.

The US has been conducting air strikes to help stem the rapid IS
advance in the north of the country.

On Monday, Iraq's president asked MP Haider al-Abadi to form a new
cabinet, snubbing the incumbent PM Nouri Maliki.

Maliki called the nomination a "violation of the constitution", but on
Tuesday ordered security forces not to intervene in the political
crisis.

In a statement published on his official website, Maliki said security
forces should instead focus on defending the country,

Abadi's appointment came after months of political infighting, which
analysts say is partially to blame for Iraq's inability to effectively
fight the IS threat.

Politicians had been unable to form a government since April's
parliamentary elections, which were won by Prime Minister Maliki.

IS fighters have seized large swathes of northern Iraq and Syria in
recent months, forcing tens of thousands of people from religious
minorities to flee their homes.

An estimated 700,000 Yazidis have been displaced since IS militants
took Sinjar from Kurdish forces defending the town, the UN says.

Keiran Dwyer, who works for the UN's office for humanitarian affairs
in Irbil, told the BBC that some Yazidis had managed to escape from
the north side of the mountain in the last 72 hours and cross the
River Tigris into Syria, where they were receiving help.

But a Yazidi relief worker, who was on board an Iraqi Air Force
helicopter evacuating the trapped refugees, described the situation as
"a genocide", with what looked like hundreds of dead people
everywhere.

"You can imagine what it's like when you land amongst 5000 people and
can only take 10 or 20, and everybody tries to get on the helicopter,"
Mirza Dinnay told the BBC.

The US, Britain and France have been delivering humanitarian aid to the Yazidis.

Over the last five nights, US and UK air crews have air-dropped more
than 310 bundles of food, water and medical supplies, and delivered
almost 72,740 litres (16,000) gallons of water and 75,000 meals, the
US government says.

The US has also reportedly begun supplying weapons to the Kurdish
forces, known as Peshmergas, who have been fighting IS in the north.